2An airplane has a mass of 3 An airplane has a mass of 3.1 x 104 kg and takes off under the influence of a constant net force of 3.7 x 104 N. What is the net force that acts on the plane’s 78 kg pilot?
4A person with a black belt in karate has a fist that has a mass of 0 A person with a black belt in karate has a fist that has a mass of 0.7 kg. Starting from rest, this fist attains a velocity of 8.0 m/s in 0.15 s. What is the magnitude of the net force applied to the fist to achieve this level of performance?
6An arrow starting from rest, leaves the bow with a speed of 25 m/s An arrow starting from rest, leaves the bow with a speed of 25 m/s. If the average force exerted on the arrow by the bow were doubled, all else remaining the same, with what speed would the arrow leave the bow?
10A 1580 kg car is traveling with a speed of 15 m/s A 1580 kg car is traveling with a speed of 15 m/s. What is the magnitude of the horizontal net force that is required to bring the car to a halt in a distance of 50 m?
12During a circus performance, a 72 kg human cannonball is shot out of an 18 m long cannon. If the human cannonball spends 0.95 s in the cannon, determine the average net force exerted on him in the barrel of the cannon.
14The drawing shows three objects The drawing shows three objects. They are connected by strings that pass over frictionless pulleys. The objects move, and the coefficient of kinetic friction between the middle object and the surface of the table is 0.1 What is the acceleration of the three objects?
16Three spheres are located at the corners of an equilateral triangle Three spheres are located at the corners of an equilateral triangle. Each side of the triangle has a length of 1.2 m. Two of the spheres have a mass of 2.8 kg each. The third sphere (mass unknown) is released from rest. Considering only the gravitational forces that the spheres exert on each other, what is the magnitude of the initial acceleration of the third sphere?
18A neutron star has a mass of 2. 0 x 1030 kg and a radius of 5 A neutron star has a mass of 2.0 x 1030 kg and a radius of 5.0 x 103 m. Suppose and object falls from rest near the surface of such a star. How fast would it be moving after in had fallen a distance of 0.01 m?